Featured Research

from universities, journals, and other organizations

Revolutionary solar cells double as lasers

Date:
March 28, 2014
Source:
University of Cambridge
Summary:
Latest research finds that the trailblazing 'perovskite' material used in solar cells can double up as a laser, strongly suggesting the astonishing efficiency levels already achieved in these cells is only part of the journey.

Latest research finds that the trailblazing 'perovskite' material used in solar cells can double up as a laser, strongly suggesting the astonishing efficiency levels already achieved in these cells is only part of the journey.
Credit: Image courtesy of University of Cambridge

Latest research finds that the trailblazing 'perovskite' material used in solar cells can double up as a laser, strongly suggesting the astonishing efficiency levels already achieved in these cells is only part of the journey.

Commercial silicon-based solar cells -- such as those seen on the roofs of houses across the country -- operate at about 20% efficiency for converting the Sun's rays into electrical energy. It's taken over 20 years to achieve that rate of efficiency.

A relatively new type of solar cell based on a perovskite material -- named for scientist Lev Perovski, who first discovered materials with this structure in the Ural Mountains in the 19th century -- was recently pioneered by an Oxford research team led by Professor Henry Snaith.

Perovskite solar cells, the source of huge excitement in the research community, already lie just a fraction behind commercial silicon, having reached a remarkable 17% efficiency after a mere two years of research -- transforming prospects for cheap large-area solar energy generation.

Now, researchers from Professor Sir Richard Friend's group at Cambridge's Cavendish Laboratory -- working with Snaith's Oxford group -- have demonstrated that perovskite cells excel not just at absorbing light but also at emitting it. The new findings, recently published online in the Journal of Physical Chemistry Letters, show that these 'wonder cells' can also produce cheap lasers.

By sandwiching a thin layer of the lead halide perovskite between two mirrors, the team produced an optically driven laser which proves these cells "show very efficient luminescence" -- with up to 70% of absorbed light re-emitted.

The researchers point to the fundamental relationship, first established by Shockley and Queisser in 1961, between the generation of electrical charges following light absorption and the process of 'recombination' of these charges to emit light.

Essentially, if a material is good at converting light to electricity, then it will be good at converting electricity to light. The lasing properties in these materials raise expectations for even higher solar cell efficiencies, say the Oxbridge team, which -- given that perovskite cells are about to overtake commercial cells in terms of efficiency after just two years of development -- is a thrilling prospect.

"This first demonstration of lasing in these cheap solution-processed semiconductors opens up a range of new applications," said lead author Dr Felix Deschler of the Cavendish Laboratory. "Our findings demonstrate potential uses for this material in telecommunications and for light emitting devices."

Most commercial solar cell materials need expensive processing to achieve a very low level of impurities before they show good luminescence and performance. Surprisingly these new materials work well even when very simply prepared as thin films using cheap scalable solution processing.

The researchers found that upon light absorption in the perovskite two charges (electron and hole) are formed very quickly -- within 1 picosecond -- but then take anywhere up to a few microseconds to recombine. This is long enough for chemical defects to have ceased the light emission in most other semiconductors, such as silicon or gallium arsenide. "These long carrier lifetimes together with exceptionally high luminescence are unprecedented in such simply prepared inorganic semiconductors," said Dr Sam Stranks, co-author from the Oxford University team.

"We were surprised to find such high luminescence efficiency in such easily prepared materials. This has great implications for improvements in solar cell efficiency," said Michael Price, co-author from the group in Cambridge.

Added Snaith: "This luminescent behaviour is an excellent test for solar cell performance -- poorer luminescence (as in amorphous silicon solar cells) reduces both the quantum efficiency (current collected) and also the cell voltage."

Scientists say that this new paper sets expectations for yet higher solar cell performance from this class of perovskite semiconductors. Solar cells are being scaled up for commercial deployment by the Oxford spin-out, Oxford PV Ltd. The efficient luminescence itself may lead to other exciting applications with much broader commercial prospects -- a big challenge that the Oxford and Cambridge teams have identified is to construct an electrically driven laser.


Story Source:

The above story is based on materials provided by University of Cambridge. The original story is licensed under a Creative Commons Licence. Note: Materials may be edited for content and length.


Journal Reference:

  1. Felix Deschler, Michael Price, Sandeep Pathak, Lina Klintberg, David Dominik Jarausch, Ruben Higler, Sven Huettner, Tomas Leijtens, Samuel David Stranks, Henry J. Snaith, Mete Atature, Richard T. Phillips, Richard H. Friend. High Photoluminescence Efficiency and Optically-Pumped Lasing in Solution-Processed Mixed Halide Perovskite Semiconductors. The Journal of Physical Chemistry Letters, 2014; 140324121627005 DOI: 10.1021/jz5005285

Cite This Page:

University of Cambridge. "Revolutionary solar cells double as lasers." ScienceDaily. ScienceDaily, 28 March 2014. <www.sciencedaily.com/releases/2014/03/140328085540.htm>.
University of Cambridge. (2014, March 28). Revolutionary solar cells double as lasers. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2014/03/140328085540.htm
University of Cambridge. "Revolutionary solar cells double as lasers." ScienceDaily. www.sciencedaily.com/releases/2014/03/140328085540.htm (accessed September 21, 2014).

Share This



More Earth & Climate News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Rally Held in India Ahead of UN Summit

Climate Change Rally Held in India Ahead of UN Summit

AFP (Sep. 20, 2014) Some 125 world leaders are expected to commit to action on climate change at a UN summit Tuesday called to inject momentum in struggling efforts to tackle global warming. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
New Music With Recycled Instruments at Colombia Fest

New Music With Recycled Instruments at Colombia Fest

AFP (Sep. 19, 2014) Jars, bottles, caps and even a pizza box, recovered from the trash, were the elements used by four musical groups at the "RSFEST2014 Sonorities Recycling Festival", in Colombian city of Cali. Duration: 00:49 Video provided by AFP
Powered by NewsLook.com
Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins